1291101-66-0Relevant academic research and scientific papers
Investigations into the nucleophilic meso-substitution of f-bodipys and improvements to the synthesis of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene
Crawford, Sarah M.,Thompson, Alison
, p. 311 - 322 (2011)
A series of three F-BODIPYs, with varying levels of steric crowding about the meso-position were selected to investigate nucleophilic meso-substitution of F-BODIPYs. The synthesis of one of these F-BODIPYs, 4,4-difluoro-4-bora-3a,4a- diaza-s-indacene (totally unsubstituted dipyrrin skeleton), was optimized to give higher yields over routine literature procedures. This modified procedure involves oxidation of a dipyrromethane using p-chloranil, instead of DDQ, to give a dipyrrin which is then trapped in situ as its BF2 complex. Nucleophilic meso-alkylation of the series of F-BOIDPYs with n-butyllithium gave meso-butyl F-BODIPYs in moderate to good yields. This work represents a new, synthetically viable method for the synthesis of meso-alkylated F-BODIPYs. Extension of the nucleophilic substitution methodology to meso-arylation was possible. However, the reaction was unselective: substitution at boron, to give the boron-diaryl C-BOIDPYs, occurred preferentially to nucleophilic meso-substitution and thus a mixture of products was obtained. The Japan Institute of Heterocyclic Chemistry.
